giles@ucf-cs.UUCP (Bruce Giles) (02/29/84)
Partly in consequence of seeing the haloes around the sun last week, I
noticed that street lights seen through a fogged-up car windshield have
a colored halo. The strange thing was that there were areas of color, with
no apparent order to where a particular color occured.
My question, should anyone decide to accept it, is:
What causes the light to be broken up into colors?
Various possibilities I came up with were:
(1) Rayleigh scattering off of dust particles suspended in the
mist,
(2) Diffraction effects from very fine scratches in the windshield,
(3) Absorbtion from chemicals that may be dissolved in the mist.
I'm not very happy with any of these ideas, however. Any other ideas out
there?
ave discordia going bump in the night ...
bruce giles
decvax!ucf-cs!giles university of central florida
giles.ucf-cs@Rand-Relay orlando, florida 32816ken@ihuxq.UUCP (ken perlow) (02/29/84)
-- >>> Partly in consequence of seeing the haloes around the sun last week, I >>> noticed that street lights seen through a fogged-up car windshield have >>> a colored halo. The strange thing was that there were areas of color, >>> with no apparent order to where a particular color occured. >>> My question, should anyone decide to accept it, is: >>> What causes the light to be broken up into colors? A foggy (pun intended) recollection from a 1960's vintage optics class: Babinet's Principle. I can't even remember what it is, although it involves diffraction through multiple holes, and an equivalence between such a situation and its logical inverse (multiple points). I do remember that haloes through foggy glasses was the demonstration of Babinet's Principle. (If I still had the text, I'd restate the thing.) -- *** *** JE MAINTIENDRAI ***** ***** ****** ****** 29 Feb 84 [10 Ventose An CXCII] ken perlow ***** ***** (312)979-7261 ** ** ** ** ..ihnp4!ihuxq!ken *** ***